In typical commercial or industrial laundry processes, textile materials such as sheets, towels, wipes, garments, tablecloths, etc. are commonly laundered at elevated temperatures with alkaline detergent materials. Such detergent materials typically contain a source of alkalinity such as an alkali metal hydroxide, alkali metal silicate, alkali metal carbonate or other such base component. When the linen is treated with an alkaline detergent composition a certain amount of carryover alkalinity may occur. Carryover alkalinity refers to the chemistry that is contained within the linen (that has not been completely removed) that is available for the next step. For example, when the detergent use solution provides an alkaline environment, it is expected that the detergent use solution will provide a certain amount of carryover alkalinity for a subsequent sour treatment step unless all of the detergent use solution is removed by rinsing.
The residual components of the alkaline detergents remaining in or on the laundered item can result in fabric damage and skin irritation by the wearer of the washed fabric. This is particularly a problem with towels, sheets and garments. Sour materials contain acid components that neutralize alkaline residues on the fabric.
Another frequent problem in laundry processes are iron containing stains, such as rust, or blood, which both are difficult to remove. If not properly rinsed, remaining iron can cause permanent yellowing of fabrics. The approach to removal of blood soils to date has primarily relied upon the use of high levels of caustic, which can damage delicate fabrics and, if not properly removed and brought back to neutral pH, can result in exposure of the caustic to human skin.
Current laundry sour compositions to help remove residual alkali and for iron control generally include strong acids such as fluoroacetic acid, phosphoric acid, hydrofluoric acid, and hexafluorosilicic acid which are environmentally undesirable and/or hazardous.
As can be seen, there is a continuing need in the art for the development of iron control treatments after alkaline washing that not only prevent yellow staining of laundered fabrics, and remove residual caustic, but also that are environmentally friendly and sustainable.
It is an object of the invention to provide laundry sour compositions and methods which provide iron control and prevention of yellowing that prevent yellowing at least as well as commercially available, less environmentally friendly sour treatment alternatives.
It is an object of the present invention to provide a pre-spot, pretreatment, pre-soak, wash or post wash linen sour treatment that may be a phosphorus free formula.
It is yet another object of the invention to provide a sour treatment that is free of toxic or hazardous chemicals such as fluoroacetic acid, hydrofluoric acid, and hexafluorosilicic acid.
It is yet another object of the invention to provide a pre-spot, pretreatment, pre-soak, wash or post wash linen sour treatment that is composed of sustainable environmentally friendly ingredients.
Other objects, aspects and advantages of this invention will be apparent to one skilled in the art in view of the following disclosure, the drawings, and the appended claims.